Controlling generator



C. I. M NEIL CONTROLLING GENERATOR Original Filed Jan 16, 1929 a. E 1 j INVENTOR.

Charles 1. Mc A/ei/ ATTO/Wg.

5 output, of a generator.

Reissued Oct. 22, 1935 UNITED STATES PATENT OFFICE 19,7 38 CONTROLLING GENERATOR Charles I. McNeil, Bloomfield,

Company,

Original No. 1,896,142, dated Serial No. 332,998, January This invention relates to lating the output It has heretofore'been regulator of the for controlling the output.

embody a pair of Eclipse Machine N. Y., a corporation of tion for reissue Febru 713,213

N. J., assignor to Elmira. Heights, New York February '1, 1933, 16,1929. Applicaary 2'1, 1934, Serial No.

5Clalms. (o1. 171-2zs) controlling or reguof an electric current generator. proposed to employ a vibrating reed or armature type such as the voltage Regulators .of this type contacts which are opened and closed by an electro-magnet for purposes well understood in the art, the movements of the contacts order of 10 to 40 cycles per lators of the type are employed for controlling the voltage output transmitting apparatus of type, the action of the cont opening and closing being usually of the second. When reguof a generator used in radio the continuous wave acts results in an intermittent note in the receiver so similar in pitch to that of the other sounds in the transmitted waves as to render impossible, in the satisfactory reception of signals.

ly, one of the objects is many instances,

Accordingto provide a novel method for regulating the voltage output of a generator,

the use of which serves to objectionable effect.

Another object of voltage regulating method overcome the above the invention is to provide a applicable to control a pair oi. coacting contacts for intermittently interrupting an electric circuit, in such a way as to render the action of said contacts of relatively high frequency, such, for example, as 80 to 300 or more cycles per second.

A iurther object of the in a regulator embodying magnet, a novel ing the various coils so as t invention is to provide a multi-coil electromethod of forming and combino insure proper regulation, regardless of changes in speed of and load on the generator.

These and other objects and advantages to be derived from the use of the closed involve the inter-r invention herein diselation and relative functions of the parts and will become apparent upon an inspection of the following specification and the accompanying drawing, wherein two embodiments of the invention are illustrated; but it is to be expressly understood that the drawing is for the purpose of illustration only and is not designed as a definition of vention, reference being had for the appended claims.

In the drawing, Fig. 1 is a diagrammatic the limits of the inthis purpose to view illustrating one form of regulating apparatus embodying the present invention; and

Fig. 2 is a diagrammatic bodiment of the invention.

Referring more particular view of another emly to Fig. l, the armature of the generator to be regulated is indicated at 3, the field winding at 4, and the field resistance at 5, said winding and resistance being connected in series across the positive main 6 and the negative main 1.

The novel regulating method may be applied to a pair of contacts 8 and 9 which are normally closed and are shunted around the resistance 5. Contact 5 is mounted on a vibrating armature H! which is pivotally mounted in any suitable manner, and adjustable resilient means, such as a coil spring H is operatively connected to said armature to normally maintain contact 9 in engagement with contact 8.

An electro-magnet having a core II, which is preferably laminated, is associated with armature Ill, and spring H is so adjusted that when the voltage of the generator rises above a predetermined value, the electro-magnet is effective to overcome the tension of said spring and move contact 9 out of engagement with contact 8, whereupon the field resistance 5 is placed in circuit with the field 4. The resistance of the field circuit is now of such value as to prevent the desired amount of field current from flowing, whereupon a reduction in the generator voltage is produced. This dropping of the voltage weakens the magnetic field of the electro-magnet to such an extent that the contacts 8 and 9 are closed by spring H to short circuit resistance 5, whereupon the field fiux and armature voltage are again built up.

The core H of the electro-magnet carries a winding H which is in series with a resistance I4, the winding and resistance being connected across the mains 6 and 1 as shown. The ma netic field set up by parallel coil l3 rises or falls relatively slowly, since it varies in accordance with the changes in the voltage in the armature. The latter in turn follows the changes of current in the field. Accordingly, in regulators embodying only a coil such as is indicated at I3, the opening and closing movements of contacts 8 and 9 are relatively slow, i. e., they are of the order of 10 to cycles per second.

A method is provided for speeding up the action of the contacts, whereby the movement of the same is of a high frequency, as, for example, 80 to 300 or more cycles per second. For this purpose the core l2 carries a second winding l5 which is connected in series with a resistance 16, said winding and resistance being shunted around generator field 4 and in series with contacts 8 and 9. Coil I5 is wound in such a manner as to strengthen the magnetic field set up in core I2 55 by the coil l8, and the tension of spring II is overcome only when both coils coact to produce the desired strength of field.

When the contacts are closed, current fiows from the positive main 6 through said contacts, series coil l5. and resistance I 6, and said series coil coacts with parallel coil l3 to set up the magnetic field in core l2. When the voltage output of the generator exceeds a predetermined amount as determined by the setting of spring II, the magnetic field of the electro-magnet is sufficiently strong, due to the combined action of coils I3 and Is, to overcome the tension of spring H and move contact 9 out of engagement with contact 8. The instant the contacts open, the current in series coil l5 falls, thus producing a sudden drop in the flux of the core I2 and this drop is independent of the fall of the voltage in the armature 3. Armature I!) instantly moves to reengage contact 9 with contact 8, due to the action of spring II. A much quicker action of the contacts is thus obtained than results from the use of a single coil such as parallel coil #3 since the magnetic field produced by the latter falls relatively slowly in accordance with the drop of voltage in the armature.

The use of series coil in combination with parallel coil I3 is sufiicient to raise the frequency of the contacts to as high as 80 to 300 cycles or more per second. This change in the frequency of the contacts may not entirely eliminate the intermittent note resulting from the engagement and disengagement of the contacts, but the note will be of a much higher pitch than that oi. other sounds resulting from the intermittent waves and hence will not interfere with the reception of signals. In other words, the regulator preferably employed in practicing the present invention is so constructed as to eliminate or minimize the interference or noises in radio signals emitted by a transmitter energized by a voltage regulated generator.

The resistance units It and I6 may be employed as indicated in order to permit the use of a larger current fiow in coils l3 and IS without danger of overheating the coils as might result from winding the resistance directly on core H. The larger portion of the heat is generated in the resistance and by placing said resistance at a distance from the coil, a greater flow of current may be used for a predetermined coil temperature. Since the circuit l5, I6 is of small inductance, it acts to absorb a portion of the voltage set up in field 4 by the sudden changes in field current.

It is highly desirable that the regulator maintain the voltage constant within very narrow limits. Since the current in series coil I5'varies in proportion to the field current, which latter in turn varies with the speed of and the load on the generator, a change in the current flowing through said coil results in a slight change in the setting or the regulator.

Conversely, on decrease in the effective value of the field current (such as results from an increase in generator speed or a decrease in load) the voltage impressed upon coil l5 decreases, thereby weakening the magnetic pull. To ofiset this decrease in pull, 0011 I3 must be strengthened by increase in voltage from the generator in order to effect opening of contacts 8 and 9. There is thus a tendency for the generator voltage to rise with increase in speed or removal of load. This tendency may be overcome or at least compensated for, by the use or the arrangement shown in Fig. 2, now to be described.

In Fig. 2 there is illustrated another embodiment of the present invention wherein a change in the current flowing through coil I 5 is ineffective 5 to vary the regulator setting. For this purpose the core I! of the electro-magnet carries a third coil l8 in series with a resistance '9, said coil and resistance being in parallel with contacts 8 and 9, and also in series with coil l5.

When the contacts are open, the current flowing through coil 18 is relatively high and the current flowing through coil I5 is relatively low, and the field set up by coil I8 is acting in a direction opposite to that set up in coil I5. When the contacts are closed, substantially no current fiows through coil l8 while a relative large amount of current flows through coil l5, and, as pointed out above in connection with Fig. 1, the coils I5 and I3 coact together to set up the desired magnetic field for opening contacts 8 and 9.

As the voltage tends to rise above the desired amount, a point is reached where the field set up by coils i3 and I 5 is effective to overcome the tension of spring II and open contacts 8 and 9. :5 Immediately the field of coil I5 drops due to the decrease in current now flowing through the coil while a relatively large amount of current flows through coil I B, and the field of the latter is effective to diminish or nullify the effect of the field in coils l3 and [5. In other words, the magnetic field for holding the contacts open is very quickly destroyed and spring II is now effective without any delay to again close the contacts. Hence, the speed of the regulator is increased by the use of coil ID.

This increase is further accelerated as the speed of the generator increases, because the current in coil l8 varies as the voltage across the contacts 8 and 9, which in turn varies inversely 40 with the speed of the generator. Hence, at high speeds, (or upon removal of load) demagnetizing force of coil I8 is increased thereby causing contacts to close sooner than at low speeds, or at relatively high loads.

From the foregoing it is apparent that the addition of the coil [8 serves to increase the speed of contact operation and compensate for any tendency in the system toward a variation in voltage across the lines 6 and 1, the ultimate result being an improvement in the quality of regulation.

There is thus provided a novel method for controlling the voltage regulator which is readily adaptable to radio transmitting apparatus for maintaining constant voltage. It is to be expressiv understood however, that the said method is not limited in its use to the radio field, as will now be readily apparent to those skilled in the art, and reference will therefore be had to the appended claims for a definition oi the limits of F the invention.

What is claimed is:

1. In combination with a generator having a field winding and a field resistance, means for regulating the voltage output of said generator by intermittently placing said resistance in circuit with said field winding including a pair of coacting contacts, and means including an electro-magnet for controlling the engagement of said contacts, the electro-magnet embodying a coil in series with said contacts and in parallel with said winding and another coil in parallel with said contacts.

2. In a regulator of the type embodying a pair of coacting contacts, a pivoted armature carrying one of said contacts, yielding means for main- 18 taining said contacts closed, and an electro-magnet for opening said contacts, the electro-magnet including a core and a plurality of coils wound thereon, one of the latter being in series with said contacts and another of the same being in parallel with the contacts but in series with the first named coil. and a third coil in parallel with said contacts and the other two coils.

3. In a regulator of the type having a vibrating armature, an electro-magnet comprising a core, a coil on said core having a series relationship with said armature and a second coil on said core, the series coil being adapted to coact with said second coil to set up a predetermined field in said core and a third coil associated with said first and second coils to compensate for changes in the field induced by said third coil.

4. In a regulator of the vibrating armature type, an electro-magnet comprising a core, and a. plurality of coils wound thereon, the first and second of said coils being adapted to coact one with the other to set up a predetermined field in said core, and a third coil adapted to coact with said first and second coils, to compensate for the changes in the magnetic field resulting from said third coil.

5. In a vibrating switch type of regulator for controlling the output of an electrical circuit, the method of obtaining a high frequency vibrating action which comprises subjecting said switch to an opening magneto-motive force bearing a deflnite relation to the voltage across the output 10 i the switch, and interposing in the magnetic field of the switch a de-magnetizing factor to compensate for the changes in the frequency of vibration resulting from an increase in generator speed, or 20 a decrease in load.

CHARLES I. McNEIL. 

